Drop hammer



March 25, 19.30,- H. BCH '1,752,141

l .DROP HAMMER Filed Nov. 10. 1926 Patented Mar. 25, 193() UNITED STATES PATENToFFlcE HANS BECH, or HUQKESWAGEN, GERMANY Dnor HAMMER Application led November 10, 1926, SerialNo. 147,431, and in Germany November 14, 1925.

My invention relates to improvements in .drop hammers, and more particularly in drop hammers in which the ram is operated by a piston reciprocating within `a cylinder having a supply of steam or compressed air. In drop hammers of this type such as are now in use the ram is connected with the piston rod by means ofa rope,'or it is directly connected therewith.- As is known to those skilled in the art both constructions are objectionable. Even if ropes are properly Itreated by skilled labourers they are subject to rapid wear, and if the hammer is op-l erated by unskilled labourers the ropes are frequently broken. In constructions in which the ram is directly connected to the piston rod the said piston rod is frequently broken even if liquid brakes are interposed between the rod and the ram. Further, the

construction is comparatively high, so that in most cases the height to which the ram can be lifted is limited. The object of the improvements is to provide a drop hammer in which the aforesaid objections are obviated.

With this object in view my invention consists in providing a'hammer in which the ram is loosely engaged by the piston rod, 4and lin which the guide way for the ram is extended upwardly so far that the ram is thrown upwardly by the impact imparted thereto by the piston beyond the end of the Working stroke of the piston. Therefore the height of the hammer is comparatively small, and only the guide ways of the ram are compara- -tively high. Thus I am enabled to provide a hammer in which the ram can be thrown to a considerable height even in low work shops. 'Thus the hammer can -be provided in work shops which by reason of their small height did not allow the mounting of the hammer. .y I

For the purpose of explaining the invention an example embodying the same has been y shown in the accompanying drawing, in

in section, and

vtrolling valves z' and k are located at the side ment, the rods n of which are formed with heads d, e loosely engaging the ram g. To the bottom ends of the cylinders a suitable driving fluid such as steam or compressed air is admitted through a ieXible tube h, the supply of the pressure fluid being controlled by an intake valve z' and a discharge valve k the bodies of which are controlled in a suitable way by a lever m. As shown in the figures the cylinders b are disposed in vertical holes made in the anvil, and the conof the anvil and independently thereof. But I wish it to beunderstood that I do not limit myself to these features, and that in some cases the cylinders b are separate from the anvil, and in other cases the valves are mounted on the anvil.

When opening the intake -valve 11 the pistons o and piston rods n are thrown upwardly, and the ram g is lifted by the heads d, e of the piston rods. After closing the intake valve the ram is thrown upwardly beyond the end stroke of the pistons o, whereupon it freely falls downwardly, the piston rods d, e having been in the vmeantime returned into their initial positions. The heads 0l and e thus constitute means abutting 'the ram g to actuate the ram by giving an impulse thereto. In some cases I provide elastic means such as an air rbuffer at the top end of the guide ways f by means of which injury to the top end of the buffer is prevented and a part of the power of the upwardly moving ram is stored -and imparted to the ram at the beginning of the downward stroke. In the figures an air buffer consisting of a cylinder p and a plung-v er g is provided at the top end ofthe guide rods f. The pistonso are elastically arrested at the ends of their strokes by elasticfiuid being confined within the cylinders at the upper and lower ends thereof. As appears 10 from Fig. 1 the outlet ports 1' are located a suitable distance away from the upper head of the cylinder, and in a similar way the inpots d e', respectively, on top of the base a,

and the rods of these Vpistons pass through the lbottoms of the dash pots into the cylinders` b. These dash potsjcushion the downward movement of' the pistons o when the ram g is dropped.

While in describing the invention reference has been made to a particular example embodying the same I wishit to be understood that my invention is not limited to the construction shown in the drawing, and that various changes may be made in the general arrangement of the apparatus and the construction of its parts without departing from the invention.

I claim:

l. A power hammer, comprising an anvil formed at its sides with vertical cylindrical holes, al ram, pistons mounted in said holes for reciprocating therein and loosely engag' mg said ram, means to supply a pressure Huid to said holes below said pistons, and guiding means tor said ram.

2. A power hammer, comprising an anvil, a ram, vertical cylinders in said anvil at the sides thereof, pistonsreciprocating in said cylinders and loosely engaging` said ram, valve mechanism controlling the supply of pressure iuid to said cylinders and having a iiex1ble connection with said cylinders, and guiding means for said ram.

3. A power hammer comprising a base, an anvil thereon, a ram, a ide structure whereln the ram is guided or vertical reciprocation, said structure extending upward from the base and the height of saidv structure being limited substantially to that required for ram-travel, a cylinder associated with,

the base, a piston therein, and a piston rod having free contact with an underpart of the ram for driving the latter upward, the piston and rod being free to return to lower position while the ram is in elevated position -in the guide structure.

4f. A power hammer comprising a base, an anvil thereon, a ram, a guide structure wherein the ram is guided for vertical reciproca tion, said structure extending upward from the base and the height of said structure being limited substantially to that required yfor ram-travel, a cylinder associated with the base, a piston therein, and a piston rod having free contact with an underpart of the ram for driving the latter upward, the

to propel the ram positively only part-wayl upward in the guide structure, and means for controllably supplying propulsive fluid to the cylinder to propel the piston rod and ram rapidly and positively upward to the end of the piston-stroke, whereafter the ram travels farther upward by momentum.

5. A power hammer'comprising a base, an anvil thereon, a ram, a uide structure wherein the ram is guided or vertical reciprocation, said structure extending upward from the base and the height of said structure being limited substantially to that required for ram-travel, a cylinder associated with the base, a piston therein, and a piston rod having free contact with an underpart of the ram for driving the'latter upward, the piston and rod being free to return to lower position while the ram is in elevated position in the guide structure, the cylinder having la discharge port positioned to provide a cushioning-pocket in the cylinder to check the piston near the upper end of its stroke.

6. A power hammer comprising a base, an anvil thereon, a ram, a guide structure wherein the ram is guided for vertical reciprocation, said structure extending upward from the base and the height of said. structure being limited substantially to that required for ram-travel, a cylinder associated with the base, a piston therein, and a piston rod having free contact with an underpart of the ram for drivin the latter upward, the piston and rod being ree to return to lower position while the ram is in elevated position in the guide structure, the piston rod having near its upper end a dash-piston, and an upwardly-open dash-cylinder about the rod at the upper end of Ithe main cylinder, the dashpiston cooperating with the dash-cylinder to check the piston rod and main piston near the end of their return stroke.

7 A power hammer comprising a base, an anvil thereon, a ram, a guide structure wherein the ram is guided for vertical reciprocatioii, said structure extending upward from the base and the height of said structure being limited substantially to that required for ram-travel, a cylinder associated with the base, a piston therein, and a piston rod having free contact with an underpart of the ram for driving the latter upward, the cylinder and pistonV rod being dimensioned to propel the ram positively only part-way upward in the guide structure, and means for controllably supplying propulsive fluid to the cylinder to propel the piston rod and ram rapidly and positively upward to the end of the piston-stroke, whereafter the ram travels farther upward by momentum, and a yielding buffer at the upper end of the guide structure to check the ram at the upper end of its maximum stroke.

8. A power hammer comprising an anvil.

a ram, guides extending upwardly a considerable distance above the anvil and in which the ram is mounted for reciprocation, the height of said guides being limited substantially to that required for ram-travel, and actuatin means abutting the ram `and adapted to drive the same upwardly from the anvil, said actuating means being disconnected from the ram and having a maximum stroke less than the extent of said guides whereby the ram will be driven the full length ofthe stroke and said actuating means and so as to travel well beyond the maximum stroke thereof and until its upward momentum is expended.

9. A power hammer comprising an anvil, a ram, guides extending upwardly a considerable distance above the anvil and in which the ram is mounted for reciprocation, the height of said guides being limited substantially to that required for ram-travel, actuating meansy abutting the ram and adapted to drive the same upwardly from the anvil, said actuating means being disconnected from the ram and having a maximum stroke less than the extent of said guides 'whereby the ram will be driven the full length of the stroke of said actuating means ,and so as to travel well beyond the maximum stroke thereof and until its upward momentum is expended, said actuating means'being free to return to its initial position while-the ram is in elevated position in the guides.

10. A power hammer comprising an anvil, a ram, guides `extending upwardly a considerable distance above the anvil and in'which the ram is mounted for reciprocation, the height of said guides being limited substantially to that required for ram-travel, cylinders having pistons loosely engaging the underside of the ram and adapted, when actuated, to drive the ram upwardly from the anvil, said pistons having a maximum stroke less .than the extent of said guides whereby the ram will be driven well beyond the maximum stroke of the pistons andv until its upward momentum is expended.

11.. A power hammer comprising an anvil,-

a ram, guides extending upwardly a considverable distance above the anvil and in which the'ram is mounted for reciprocation, the height of said guides being Ilimited substantially'to that required for ramtravel, cylinders having pistons loosely engaging the underside of the ram and adapted, when vactuated, to drive the ram upwardly from the anvil, said pistons having a maximum stroke less than the extent of said guides whereby theram will be driven well beyond the maximum stroke of the pistons, and a buffer arrangedon said guides to receive the impact of said ram.

In testimony whereof I hereunto aliix my signature.

HANS BECH. 

